1. Field of the Invention
The present invention relates to an electronic apparatus and a control method thereof, and more particularly, to an electronic apparatus and a control method thereof, which can automatically control output volume.
2. Description of the Related Art
There are various conventional electronic apparatuses having a sound input/output function, for example, an audio system, a TV, a computer system, etc. In the case of the computer system, a CD-ROM drive connected to a sound card allows a user to listen to music recorded on a CD, like the audio system. Also, various sound devices can be connected to the computer system through sound input channels provided in a computer main body.
The sound card used in the computer system converts an analog sound to digital data that can be stored in an audio file, or converts digitized audio signals to analog signals that can be played on the computer's speakers. The analog signal is inputted through the sound input channel such as a microphone-in channel, a line-in channel, an auxiliary-in channel, a CD audio connector, etc., and mixed by an analog mixing circuit, and amplified by an amplifying circuit, and output to the speaker. Also, the analog signal is converted to the digital signal by an A/D converter. Further, the digitized audio signal is inputted through a system bus, mixed by a digital mixing circuit, converted to the analog signal by a D/A converter, amplified by the amplifying circuit, and output to the speaker.
Here, the mixing circuit is employed to adjust the analog/digital audio signals like a control amplifier of the audio system. The mixing circuit includes a plurality of individual volume controllers to individually control output volume levels of the audio signals input through the respective sound input channels, a mixer to mix the audio signals provided by the individual volume controllers, and a master volume controller to control the output volume of the audio signal transmitted from the mixer. With the above-described configuration, the audio signals of respective sound input channels and the mixed audio signal can be controlled in the output volume, for example, muting, turning up, and turning down.
However, the above-described computer system includes the sound input channels such as the microphone-in channel, the line-in channel, the auxiliary-in channel, etc., so that the audio signals of the respective sound input channels are simultaneously output to the speaker. Accordingly, when the user wants to listen to the sound from one of the sound input channels, output volume levels of the other sound input channels must be controlled. In the computer system, the above selective volume control is achieved by the above-described mixing circuit. The mixing circuit is operated according to a setup of a volume control program, for example, the volume controller of a speaker-icon type, wherein the volume control program is executed under an operating system such as Windows, and allows the user to set up the output volume levels of the respective sound input channels.
Hence, in the conventional electronic apparatus having the plurality of sound input channels, when the user wants to listen to the sound from a selected sound input channel, the user has to individually set up the output volume levels of the other unselected sound input channels to be muted or lowered, which is inconvenient to the user.